Morton's Steakhouse Recipe
1/4 cup unsalted butter
3/4 cup minced yellow onion
1 1/4 tablespoons minced garlic
2 teaspoons coarse salt
1 teaspoon freshly ground black pepper
3/4 teaspoon freshly grated nutmeg
1/4 cup all purpose flour
3 1/2 cups half and half
2 1/4 pounds chopped frozen spinach, thawed and squeezed dry
1/3 cup freshly grated Parmesan cheese
In large saucepan, melt butter over medium-low heat. Add onion and garlic; saute for about 10 minutes, or until onion is translucent. Stir in salt, pepper and nutmeg. Sprinkle flour over onion and cook over low heat, stirring with wooden spoon, about 4 minutes or until there is a nutty aroma. Add half and half and cook over medium-low heat, whisking occasionally, until hot. Raise heat to medium-high and bring to boil. Whisk continuously 6 to 8 minutes, or until mixture thickens.
Remove pan from heat. Using handheld immersion blender, blend sauce for 1 to 2 minutes or until smooth. Stir in spinach until well-mixed and heated through. Just before serving, set over medium heat, add Parmesan and stir until well-mixed and heated through.